-Whether at home, at work or outdoors, people spend a lot of time looking at electronic devices with screens, including computers, TVs and smartphones.
Studies suggest that blue light emitted from these screens poses health risks over time, including eye fatigue and insomnia.
This is why so-called computer glasses, which cut the amount of blue light reaching the eyes, have recently grown in popularity.
Makers of the glasses said the products fit the times and are helping to expand a market otherwise geared mainly toward improving one's eyesight. Some companies have even started purchasing computer glasses for employees as part of their benefits package. The glasses can be either prescription or nonprescription.
"Our company's president was often complaining that his eyes got tired whenever he used electronic devices like a computer or an iPad," said Yuka Hojo, a public relations official at Jin Co., which runs the Jins eyewear chain. "This is why we came up with the idea of developing computer glasses."
It took four to five years for the company to produce computer glasses with the help of eye doctors who held demonstration experiments to prove the eyewear actually eased the blue light burden, Hojo said.
In the visible spectrum, or that which humans are capable of seeing, blue light has the strongest energy.
Light-emitting diodes, which are used in many of today's electronics devices, emit more blue light compared with non-LED devices, according to the Blue Light Society, a Tokyo-based group of ophthalmologists.
The group said it has yet to be determined how significant the effect of blue light on human health is, but it is believed it tires the eyes and may affect people's daily rhythm, particularly late-night exposure, which could interrupt the sleeping cycle.
Minami Aoyama Eye Clinic in Tokyo conducted tests on employees of Microsoft Corp.'s Japan branch by using Jins computer glasses to gauge their effectiveness. The eyewear apparently eased pain in the eyes, neck, shoulder and back, and reduced glare from screens.
Jins began selling the glasses last September under the Jins PC brand, pitching them as eye-friendly for users of electronics devices.
The lenses are tinted light brown so they can absorb and cut blue light by 45 percent, the company says. A nonprescription version is also available.
Hojo said sales have been steady since their debut, with 500,000 pairs sold as of the end of July.
The company has increased its sales forecast for the coming business year, which runs September to August, by Y2.5 billion to Y22.5 billion and operating profit by Y500 million to Y2.6 billion, saying the Jins PC glasses have largely contributed to the improved prospects.
"I don't think the glasses would be this popular if they were sold just to people with poor vision," said Ema Nakajima, another PR person at Jin.
Jin has been running an ad blitz involving various media, including TV commercials, but Hojo attributed the popularity of the glasses to word of mouth, including praise from systems engineers who use computers all day.
Yukio Fujita, who works in marketing and sales at Shizuoka-based Meganetop Co., said tinted computer glasses have been on the market for some years, but they have recently become more popular among people with good vision amid the spread of smartphones.